[FOM] Re: "Galaxies"

Martin Davis martin at eipye.com
Sat Aug 2 12:47:27 EDT 2003


On August 1, V. Kanovei wrote:

 >Generally, by van den Berg, a galaxy is a countable
 >union of internal sets (a halo a countable intersection).

The quite different definition I gave in a previous post is from Robinson's 
monograph NONSTANDARD ANALYSIS in the chapter on metric spaces.

Alas, I'm ignorant of van den Berg's work.

Martin




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